Cooling systems typically use circulating fluid or coolant to absorb heat from various components of the machine. The circulating fluid absorbs heat from various components thus removing it therefrom as it flows through the cooling system. The heat or thermal energy collected is removed from the fluid, typically in a radiator or another similar device.
Known cooling systems are effective in cooling various components of a vehicle but have limitations as to their operating temperatures and system requirements. For example, the heat absorption capacity of a liquid-coolant system depends on the flow rate of the coolant as well as on the total volume of coolant in the system. One disadvantage of liquid-coolant systems is their implementation in applications having weight restrictions because of the weight of the fluid and related cooling system components that are carried onboard the vehicle. In applications having both weight restrictions in addition to requiring the removal of large amount of heat, adequate cooling using a liquid-based cooling system may not be practical and may also add weight and complexity to the vehicle.
Another disadvantage of liquid-coolant systems is the electrical conductivity of the cooling medium. Because water is typically a main component of a liquid-coolant mixture, the electrical conductivity that is inherent to such mixtures makes their use unsuitable for cooling electrical components internally, such as generators and motors. Electric drive vehicles must rely on use of other mediums, such as air, for cooling. As is known, the heat capacity of air is lower than that of water or a liquid-based coolant, which means that a large volume of air must be used to match the cooling capacity of a liquid-based coolant. The energy expended to move large volumes of air around and through various components of the vehicle reduces the fuel or energy efficiency of the vehicle. Moreover, cooling systems using air, especially when used to cool more than one areas or components of the vehicle, require ducts that extend to the various components of the vehicle. Such ducts are usually large to accommodate the high volumes of air flowing to cool each components, which makes the routing of the ducts and the positioning of components in the design of the vehicle more complex and costly.